Dioscorea alata

Because it has become naturalized following its origins in Asia, specifically the Philippines, through tropical South America, and the southeastern U.S., D. alata is referred to by many different names in these regions. In English alone, aside from purple yam, other common names include ten-months yam, water yam, white yam, winged yam, violet yam, Guyana arrowroot, or simply yam.

{{missing information|wild relatives (D. nummularia, D. transverse, and D. hastifolia; progenitor unknown) [doi:10.1111/boj.12374])|date=October 2021}}

File:Ubejf1680.JPG

Dioscorea alata is one of the most important staple crops in Austronesian cultures. It is one of various species of yams that were domesticated and cultivated independently within Island Southeast Asia and New Guinea for their starchy tubers, including the round yam (Dioscorea bulbifera), ubi gadung (Dioscorea hispida), lesser yam (Dioscorea esculenta), Pacific yam (Dioscorea nummularia), fiveleaf yam (Dioscorea pentaphylla), and pencil yam (Dioscorea transversa).{{cite journal |last1=Barker |first1=Graeme |last2=Hunt |first2=Chris |last3=Barton |first3=Huw |last4=Gosden |first4=Chris |last5=Jones |first5=Sam |last6=Lloyd-Smith |first6=Lindsay |last7=Farr |first7=Lucy |last8=Nyirí |first8=Borbala |last9=O'Donnell |first9=Shawn |title=The 'cultured rainforests' of Borneo |journal=Quaternary International |date=August 2017 |volume=448 |pages=44–61 |doi=10.1016/j.quaint.2016.08.018 |url=http://researchonline.ljmu.ac.uk/4693/3/The%20cultured%20rainforests%20of%20Borneo.pdf |bibcode=2017QuInt.448...44B}} Among these, D. alata and D. esculenta were the only ones regularly cultivated and eaten, while the rest were usually considered as famine food due to their higher levels of the toxin dioscorine which requires that they be prepared correctly before consumption.{{cite journal |last1=Bevacqua |first1=Robert F. |title=Origin of Horticulture in Southeast Asia and the Dispersal of Domesticated Plants to the Pacific Islands by Polynesian Voyagers: The Hawaiian Islands Case Study |journal=HortScience |date=1994 |volume=29 |issue=11 |pages=1226–1229 |url=http://hortsci.ashspublications.org/content/29/11/1226.full.pdf |doi=10.21273/HORTSCI.29.11.1226 |doi-access=free}} D. alata is also cultivated more than D. esculenta, largely because of its much larger tubers.{{cite web |url=http://www.temarareo.org/PPN-Qubi.html |title=*Qufi ~ Uwhi, uhi |work=Te Mära Reo: The Language Garden |publisher=Benton Family Trust|access-date=21 January 2019}}

D. alata and D. esculenta were the most suitable for long transport in Austronesian ships and were carried through all or most of the range of the Austronesian expansion. D. alata in particular were introduced into the Pacific Islands and New Zealand. They were also carried by Austronesian voyagers into Madagascar and the Comoros.{{cite journal |last1=Crowther |first1=Alison |last2=Lucas |first2=Leilani |last3=Helm |first3=Richard |last4=Horton |first4=Mark |last5=Shipton |first5=Ceri |last6=Wright |first6=Henry T. |last7=Walshaw |first7=Sarah |last8=Pawlowicz |first8=Matthew |last9=Radimilahy |first9=Chantal |last10=Douka |first10=Katerina |last11=Picornell-Gelabert |first11=Llorenç |last12=Fuller |first12=Dorian Q. |last13=Boivin |first13=Nicole L. |title=Ancient crops provide first archaeological signature of the westward Austronesian expansion |journal=Proceedings of the National Academy of Sciences |date=14 June 2016 |volume=113 |issue=24 |pages=6635–6640 |doi=10.1073/pnas.1522714113 |pmid=27247383 |pmc=4914162|bibcode=2016PNAS..113.6635C |doi-access=free }}{{cite journal |last1=Beaujard |first1=Philippe |title=The first migrants to Madagascar and their introduction of plants: linguistic and ethnological evidence |journal=Azania: Archaeological Research in Africa |date=August 2011 |volume=46 |issue=2 |pages=169–189 |doi=10.1080/0067270X.2011.580142 |s2cid=55763047 |url=https://halshs.archives-ouvertes.fr/halshs-00706173/file/Beaujard.azania2.pdf}}{{cite book |last1=Walter |first1=Annie |last2=Lebot |first2=Vincent |title=Gardens of Oceania |date=2007 |publisher=IRD Éditions-CIRAD |isbn=9781863204705 |url=https://books.google.com/books?id=SMYkLkV4iyEC}}

File:Starr 061106-9589 Dioscorea alata.jpg

The center of origin of purple yam is in the Philippines, but archaeological evidence suggests that it was exploited in Island Southeast Asia and New Guinea before the Austronesian expansion. Purple yam is believed to be a true cultigen, only known from its cultivated forms. The vast majority of cultivars are sterile, which restricts its introduction into islands purely by human agency, making them a good indicator of human movement. Some authors have proposed, without evidence, an origin in Mainland Southeast Asia, but it shows the greatest phenotypic variability in the Philippines and New Guinea.{{cite journal |last1=Malapa |first1=R. |last2=Arnau |first2=G. |last3=Noyer |first3=J.L. |last4=Lebot |first4=V. |title=Genetic Diversity of the Greater Yam (Dioscorea alata L.) and Relatedness to D. nummularia Lam. and D. transversa Br. as Revealed with AFLP Markers |journal=Genetic Resources and Crop Evolution |date=November 2005 |volume=52 |issue=7 |pages=919–929 |doi=10.1007/s10722-003-6122-5|bibcode=2005GRCEv..52..919M |s2cid=35381460 }}{{cite journal |last1=Cruz |first1=V.M.V. |last2=Altoveros |first2=N.C. |last3=Mendioro |first3=M.S. |last4=Ramirez |first4=D.A. |title=Geographical patterns of diversity in the Philippine edible yam collection |journal=Plant Genetic Resources Newsletter |date=1999 |volume=119 |pages=7–11}}{{cite journal |last1=Paz |first1=Victor J. |title=Neolithic Human Movement to Island Southeast Asia: The Search for Archaeobotanical Evidence |journal=Indo-Pacific Prehistory Association Bulletin |date=1999 |volume=18 |issue=Melaka Papers Vol. 2 |pages=151–158 |doi=10.7152/bippa.v18i0.11710 |doi-broken-date=November 1, 2024 |url=https://journals.lib.washington.edu/index.php/BIPPA/article/viewFile/11710/10339}}

Based on archaeological evidence of early farming plots and plant remains in the Kuk Swamp site, authors have suggested that it was first domesticated in the highlands of New Guinea from around 10,000 BP and spread into Island Southeast Asia via the Lapita culture at around c. 4,000 BP, along with D. nummularia and D. bulbifera. In turn, D. esculenta is believed to have been introduced by the Lapita culture into New Guinea. There is also evidence of an agricultural revolution during this period brought by innovations from contact with Austronesians, including the development of wet cultivation.{{cite journal |last1=Chaïr |first1=H. |last2=Traore |first2=R. E. |last3=Duval |first3=M. F. |last4=Rivallan |first4=R. |last5=Mukherjee |first5=A. |last6=Aboagye |first6=L. M. |last7=Van Rensburg |first7=W. J. |last8=Andrianavalona |first8=V. |last9=Pinheiro de Carvalho |first9=M. A. A. |last10=Saborio |first10=F. |last11=Sri Prana |first11=M. |last12=Komolong |first12=B. |last13=Lawac |first13=F. |last14=Lebot |first14=V. |last15=Chiang |first15=Tzen-Yuh |title=Genetic Diversification and Dispersal of Taro (Colocasia esculenta (L.) Schott) |journal=PLOS ONE |date=17 June 2016 |volume=11 |issue=6 |pages=e0157712 |doi=10.1371/journal.pone.0157712 |pmid=27314588 |pmc=4912093 |bibcode=2016PLoSO..1157712C|doi-access=free }}{{cite book |first1=Tim |last1=Bayliss-Smith |first2=Jack |last2=Golson |first3=Philip |last3=Hughes|editor1-first=Jack |editor1-last=Golson |editor2-first=Tim |editor2-last=Denham|editor3-first=Philip |editor3-last=Hughes|editor4-first=Pamela|editor4-last= Swadling|editor5-first=John |editor5-last=Muke |title=Ten Thousand Years of Cultivation at Kuk Swamp in the Highlands of Papua New Guinea |chapter=Phase 4: Major Disposal Channels, Slot-Like Ditches and Grid-Patterned Fields |publisher=ANU Press |series=terra australis |volume=46 |year=2017 |pages=239–268 |isbn=9781760461164|chapter-url =https://books.google.com/books?id=Hlk0DwAAQBAJ&pg=PA239}}

However, much older remains identified as being probably D. alata have also been recovered from the Niah Caves of Borneo (Late Pleistocene, <40,000 BP) and the Ille Cave of Palawan (c. 11,000 BP), along with remains of the toxic ubi gadung (D. hispida) which requires processing before it can be edible. Although it doesn't prove cultivation, it does show that humans already had the knowledge to exploit starchy plants and that D. alata were native to Island Southeast Asia. Furthermore, it opens the question on whether D. alata is a true species or cultivated much older than believed.{{cite journal |last1=Barker |first1=Graeme |last2=Lloyd-Smith |first2=Lindsay |last3=Barton |first3=Huw |last4=Cole |first4=Franca |last5=Hunt |first5=Chris |last6=Piper |first6=Philip J. |last7=Rabett |first7=Ryan |last8=Paz |first8=Victor |last9=Szabó |first9=Katherine |title=Foraging-farming transitions at the Niah Caves, Sarawak, Borneo |journal=Antiquity |date=2011 |volume=85 |issue=328 |pages=492–509 |doi=10.1017/S0003598X00067909 |s2cid=131187696 |doi-access=free}}{{cite journal |last1=Balbaligo |first1=Yvette |title=A Brief Note on the 2007 Excavation at Ille Cave, Palawan, the Philippines |journal=Papers from the Institute of Archaeology |date=15 November 2007 |volume=18 |issue=2007 |pages=161 |doi=10.5334/pia.308 |doi-access=free}}{{cite journal |last1=Barton |first1=Huw |title=The Case for Rainforest Foragers: The Starch Record at Niah Cave, Sarawak |journal=Asian Perspectives |date=2005 |volume=44 |issue=1 |pages=56–72 |url=https://core.ac.uk/download/pdf/5105493.pdf |doi=10.1353/asi.2005.0005 |hdl=10125/17222 |s2cid=11596542 |hdl-access=free}}{{cite book |first1=Huw |last1=Barton |first2=Timothy |last2=Denham |editor1-first=Grame |editor1-last=Barker |editor2-first=Monica |editor2-last=Janowski |title=Why cultivate? Anthropological and Archaeological Approaches to Foraging–Farming Transitions in Southeast Asia |chapter=Prehistoric vegeculture and social life in Island Southeast Asia and Melanesia |publisher=McDonald Institute for Archaeological Research |year=2011 |pages=61–74 |isbn=9781902937588 |chapter-url=http://austronesian.linguistics.anu.edu.au/historydownloads/Barton_Denham_2011.pdf |access-date=2019-01-21 |archive-date=2019-03-28 |archive-url=https://web.archive.org/web/20190328172327/http://austronesian.linguistics.anu.edu.au/historydownloads/Barton_Denham_2011.pdf |url-status=dead }}{{cite book |first1=Tim |last1=Reynolds |first2=Graeme |last2=Barker |first3=Huw |last3=Barton |first4=Gathorne |last4=Cranbrook |first5=Chris |last5=Hunt |first6=Lisa |last6=Kealhofer |first7=Victor |last7=Paz |first8=Alasdair |last8=Pike |first9=Philip |last9=Piper|first10=Ryan |last10=Rabett |first11=Gary |last11=Rushworth |first12=Christopher |last12=Stimpson |first13=Katherine |last13=Szabó|editor1-first=Graeme|editor1-last=Barker |title=Rainforest Foraging and Farming in Island Southeast Asia |chapter=The First Modern Humans at Niah, c. 50,000–35,000 Years Ago |publisher=McDonald Institute for Archaeological Research |year=2013 |pages=133–170 |isbn=9781902937540|chapter-url =https://pages.upd.edu.ph/sites/default/files/pawlik/files/niah_ch04_the_first_modern_humans_at_niah.pdf}}

Purple yam remains an important crop in Southeast Asia, particularly in the Philippines where the vividly purple variety is widely used in various traditional and modern desserts. It also remains important in Melanesia, where it is also grown for ceremonial purposes tied to the size of the tubers at harvest time. Its importance in eastern Polynesia and New Zealand, however, has waned after the introduction of other crops, most notably the sweet potato.

Purple yams have edible tubers which have a mildly sweet, earthy and nutty taste, reminiscent of sweet potatoes or taro. The violet cultivars, in particular, turn dishes distinctively vivid violet because of the high amount of anthocyanins.{{cite web |last1=Sutherlin |first1=Margaret |title=Everything You Need to Know About Ube, The Purple Yam |url=https://www.chowhound.com/food-news/189640/everything-you-need-to-know-about-ube-the-purple-yam/ |website=Chowhound |access-date=18 May 2019}} Purple yams are also valued for the starch that can be processed from them.

Purple yam is most common in Philippine cuisine (where it is known as ube or ubi). It is widely applied for many Philippine desserts, such as ube cake, ube cheesecake and ube crinkles, as well as an ingredient or flavor for ice cream, milk, donuts, tarts, jam and other types of pastries. It is often eaten boiled, baked, or as a sweetened dessert called ube halayá; the latter being a popular ingredient in the iced dessert called halo-halo.{{cite news |last1=Kearns |first1=Landess |title=Ube Is The Natural Ingredient That Turns Food Perfectly Purple |url=https://www.huffpost.com/entry/ube-purple-yam_n_57e19ec0e4b0e28b2b50c17f |access-date=18 May 2019 |work=The Huffington Post}}{{cite web |last1=Bueno |first1=Anna |title=All hail ube, the culinary gem we took for granted |url=http://nine.cnnphilippines.com/life/leisure/food/2016/10/14/ube-cover-story.html |website=CNN Philippines |access-date=18 May 2019 |archive-date=1 November 2019 |archive-url=https://web.archive.org/web/20191101191518/http://nine.cnnphilippines.com/life/leisure/food/2016/10/14/ube-cover-story.html |url-status=dead }}{{cite web |last1=Valdeavilla |first1=Ronica |title=Ube: The Philippine Purple Yam (More Popular Than Vanilla!) |url=https://theculturetrip.com/asia/philippines/articles/ube-the-philippine-purple-yam-more-popular-than-vanilla/ |website=culture trip |date=6 June 2018 |access-date=18 May 2019}} Purple yam desserts have more recently entered the United States through Philippine cuisine, under the Filipino name "ube". It is particularly popular due to the striking violet-purple color it gives to desserts.{{cite web |url=http://abc7chicago.com/food/donut-shop-in-gurnee-cranks-out-unique-freshly-made-donuts/1602514/ |title=Donut Shop in Gurnee Cranks Out Unique Freshly Made Donuts |date=November 11, 2016 |publisher=ABC7 Chicago}}

Purple yam is commonly confused with purple/violet varieties of sweet potatoes because of their similarities in color, taste, and culinary uses. However, like other yams, purple yam tends to have a moister texture than sweet potatoes. Purple yams also have higher anthocyanin content than sweet potatoes. They can otherwise be used interchangeably in most recipes.{{cite web |title=Ube or Not Ube, That Is the Question…and Frieda's Is Answering |url=https://www.friedas.com/ube-or-not-ube-that-is-the-questionand-friedas-is-answering/ |website=Frieda's |date=17 April 2017 |access-date=18 May 2019}}{{cite web |title=Ingredient Spotlight: Ube, the Purple Yams That Make Dessert |url=https://www.onegreenplanet.org/vegan-food/ingredient-spotlight-ube/ |website=OneGreenPlanet |access-date=18 May 2019 |date=2017-03-24}}

Ube halaya, Filipino dessert.jpg|Ube halaya (mashed purple yam) from the Philippines

Ube champorado.jpg|Ube champorado from the Philippines

Piaya flatbread (Philippines) 01.jpg|Ube and muscovado piayas from the Philippines

Undhiyu.jpg|Undhiyu from Gujarat, India

Okinawan sweet potato pancakes with coconut ube sauce.jpg|Okinawan sweet potato pancakes with coconut ube sauce

Ube crepe cake.jpg|A slice of ube crepe cake

Ubecupcakes.jpg|Purple yam cupcakes with flan top layers

Ube doughnut.jpg|Filipino ube donut

File:Ube_Mamón1.jpg |Ube Mamón

Halo-Halo.jpg|Halo-halo with ube halaya

Although available as a dietary supplement and used in folk medicine, there is no clinical evidence that D. alata has any therapeutic properties.{{cite web |title=Wild yam |url=https://www.drugs.com/mtm/wild-yam.html |publisher=Drugs.com |access-date=15 March 2021 |date=24 July 2020}} Use of D. alata supplements may have adverse effects in people taking estrogens, anticoagulant drugs or during pregnancy and breast-feeding. Some people may have allergic reactions to use of D. alata supplements.

D. alata has relatively high levels of oxalates (486–781 mg/100 g dry matter),{{cite journal |vauthors=Wanasundera JP, Ravindran G |s2cid=36080604 |title=Nutritional assessment of yam (Dioscorea alata) tubers |journal=Plant Foods Hum Nutr |volume=46 |issue=1 |pages=33–9 |year=1994 |pmid=7971785 |doi=10.1007/BF01088459|bibcode=1994PFHN...46...33W }} which are associated with antinutritional effects and kidney stone formation.{{cite journal |last1=Otegbayo |first1=B. O. |last2=Oguniyan |first2=D. J. |last3=Olunlade |first3=B. A. |last4=Oroniran |first4=O. O. |last5=Atobatele |first5=O. E. |title=Characterizing genotypic variation in biochemical composition, anti-nutritional and mineral bioavailability of some Nigerian yam (Dioscorea spp.) land races |journal=Journal of Food Science and Technology |volume=55 |issue=1 |date=2017-11-01 |issn=0022-1155 |pmid=29358812 |pmc=5756202 |doi=10.1007/s13197-017-2913-0 |pages=205–216}}

The color of purple varieties is due to various anthocyanin pigments.{{cite journal |vauthors=Moriya C, Hosoya T, Agawa S, Sugiyama Y, Kozone I, Shin-Ya K |title=New acylated anthocyanins from purple yam and their antioxidant activity. |journal=Biosci Biotechnol Biochem |year=2015 |volume=79 |issue=9 |pages=1484–92 |pmid=25848974 |doi=10.1080/09168451.2015.1027652 |s2cid=11221328 |doi-access=free }} The pigments are water-soluble, and have been proposed as possible food coloring agents.{{cite journal |last1=Li |first1=Jinwei |last2=Zhang |first2=Lianfu |last3=Liu |first3=Yuanfa |year=2013 |title=Optimization of Extraction of Natural Pigment from Purple Sweet Potato by Response Surface Methodology and Its Stability |journal=Journal of Chemistry |volume=2013 |pages=1–5 |doi=10.1155/2013/590512 | doi-access = free}} D. alata is sometimes grown in gardens for its ornamental value.

Dioscorea alata is native to the Philippines, as well as surrounding areas (Taiwan and the Ryukyu Islands of Japan). It has escaped from its native growth area and into the wild in many other places, becoming naturalized in parts of southern and east-central China, Africa and Madagascar, the Western Hemisphere, and various islands in the Indian and Pacific oceans.[http://apps.kew.org/wcsp/namedetail.do?name_id=239747 Kew World Checklist of Selected Plant Families][http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200028084 Flora of China, Vol. 24 Page 296, shen shu, Dioscorea alata Linnaeus, Sp. Pl. 2: 1033. 1753. ] It persists in the wild in Haiti, as well as the United States, in Hawaii, Louisiana, Georgia, Alabama, Puerto Rico, the U.S. Virgin Islands, and in Florida where it is considered an invasive species.{{ cite web |url=http://plants.usda.gov/java/profile?symbol=DIAL2 |title=Profile for Dioscorea alata (water yam) |work=PLANTS Database |publisher=USDA, NRCS |access-date=May 26, 2011}}[http://bonap.net/MapGallery/County/Dioscorea%20alata.png Biota of North America Program, 2013 county distribution map]

File:Starr 061106-1435 Dioscorea alata.jpg|Purple yam leaves

File:Starr-061106-1437-Dioscorea alata-flowers-Maui Nui Botanical Garden-Maui (24572888200).jpg|Purple yam flowers

• Domesticated plants and animals of Austronesia
• Colocasia esculenta
• Alocasia macrorrhizos
• Amorphophallus paeoniifolius
• Cyrtosperma merkusii
• Ipomoea batatas

{{Reflist}}

{{Commons category|Dioscorea alata|Dioscorea alata}}

{{Wikispecies|Dioscorea alata|Dioscorea alata}}

• {{ITIS |id=43372 |taxon=Dioscorea alata |access-date=18 February 2006}}
• [http://www.forestryimages.org/browse/subimages.cfm?sub=5535&search=Search Images] {{Webarchive|url=https://web.archive.org/web/20120320071314/http://www.forestryimages.org/browse/subimages.cfm?sub=5535&search=Search |date=March 20, 2012 }} from Forestry Images (webpages from the University of Georgia's Center for Invasive Species and Ecosystem Health)

{{Taxonbar|from=Q1932852}}

alata

Category:Plants described in 1753

Category:Taxa named by Carl Linnaeus

Category:Yams (vegetable)

Category:Flora of tropical Asia

Category:Maharashtrian cuisine

Category:Filipino cuisine

Category:Austronesian agriculture